1. Field of the Invention
This invention concerns an illuminated light system including a changeable letter or other indicia for use with illuminated signs which presents different appearances when backlit and frontlit. More particularly, it concerns a changeable letter including a translucent plate bearing plural layers of superposed indicia-defining material, the materials being of contrasting colors.
2. Description of the Prior Art
Signage materials are presently offered which permit the user to select and display a desired message by interchanging different letters, symbols and numbers (collectively referred to herein as "letters"). These signs are well known, and typically include a source of illumination over which is placed a translucent panel. These panels, typically of colored plastic, enclose a box having a light source such as fluorescent or incandescent bulbs therein. The lights may be powered by an electrical source such as a battery, connected by an electric cord to an electrical outlet, or permanently wired to a fixed electrical power supply.
The letters are typically formed of an opaque material which is black or of another color. By placing the letters along tracks, a message can be presented on the sign. This is a convenient, durable and relative inexpensive way to present a message which can be readily altered as prices or other circumstances dictate.
However, in order to conserve energy, it may be desirable to turn the lights off during the daytime. When this is done, the letters are no longer lighted from the back (backlit) by the lights inside the box, but instead are illuminated by sunlight or other lighting from the front (frontlit). Depending on the color of the translucent panel, the solid color letters of the prior art may be more difficult to read in the daytime than at night. In addition, there may be circumstances where contrasting colors on the same letters, for example a light letter with a dark surrounding border, would enhance daytime visibility. There has thus arisen a need for a changeable letter system which is readily visible both when backlit and frontlit and is useful both in daytime and nighttime situations.